Inclusion of island catchment "type" feature within divides layer of the hydrofabric

[jduckerOWP]

To properly discard island features within an unstructured mesh generation of a given VPU region of the hydrofabric, we need to add a flag within the "type" column of the "divides" layer in the hydrofabric geopackage files to indicate when a given catchment id is considered as an island feature. Our proposal is simply to just relabel island catchment ids as an "island" within the "type" column instead of "coastal". Let me know if you have any questions or concerns and thanks Mike!